The invention relates to a motor-driven saw having a gearing housing, which has at least two housing parts, a reciprocating rod, which when operating executes a reciprocating movement in the direction of a stroke axis, and an openable and closable reciprocating movement actuator, by which the stroke movement can be superimposed with a pendular movement made transverse to the stroke axis.
Saws of this type are also known as “key-hole saws.” The reciprocating stroke movement of the saw produces an improved advance feed power principally when working on wood. In contrast, when working metal, the reciprocating stroke movement has certain drawbacks. Devices are known, in which the reciprocating movement can be changed or can be turned off to obtain a purely linear stroke movement.
U.S. Pat. No. 6,212,781 discloses a saber saw with two housing halves with each accommodating a bearing bar of a stroke bar guide system. In this fashion, the stroke bar guide system can be pivoted about the axis of the two bearing bars relative to a stroke axis. At one of the ends of the guide pin facing away from the stroke bar guide system, the latter has an actuator pin oriented towards the rear end of the saw, the actuator pin projects into the guide slot of an adjustment/setting element. The housing halves each have a rectangular recess in a zone, in which both halves abut on the top part of the saw, whereby both recesses lie adjacent to each other and form a common receptacle for the setting element. By operating the setting element, the actuating pin is positioned vertical to the stroke axis over the guide slot, whereby the inclination of the stroke bar guide system and the force of the oscillating movement can be set.
This type of procedure requires relatively stable bearing zones in both housing parts for the studs, since relatively powerful forces act on the stroke bar guide system in operation. On the other hand, the sufficiently stable and deformation resistant connection of both housing parts must be assured. As a result, high material costs are incurred.
In addition, the assembly of the stroke bar guide system and the adjustment device between the two housing parts is relatively costly. Furthermore, in the bearing method of the adjusting device provided here, complete sealing of the gearing housing to the outside can be achieved only with considerable difficulty. Overall, high manufacturing costs are the result.